Superconducting Quantum Interference at the Atomic Scale

Abstract

A single spin in a Josephson junction can reverse the flow of the supercurrent. At mesoscopic length scales, such $\pi$-junctions are employed in various instances from finding the pairing symmetry to quantum computing. In Yu-Shiba-Rusinov (YSR) states, the atomic scale counterpart of a single spin in a superconducting tunnel junction, the supercurrent reversal so far has remained elusive. Using scanning tunneling microscopy (STM), we demonstrate such a 0 to $\pi$ transition of a Josephson junction through a YSR state as we continuously change the impurity-superconductor coupling. We detect the sign change in the critical current by exploiting a second transport channel as reference in analogy to a superconducting quantum interference device (SQUID), which provides the STM with the required phase sensitivity. The measured change in the Josephson current is a signature of the quantum phase transition and allows its characterization with unprecedented resolution.

10 pages, 6 figures, including supplementary information

References in corpus (6)

• Supercurrent reversal in quantum dots
• Energy resolution and discretization artefacts in the numerical renormalization group
• Critical Current Oscillations in Strong Ferromagnetic Pi-Junctions
• Microscopic resolution of the interplay of Kondo screening and superconducting pairing: Mn-phthalocyanine molecules adsorbed on superconducting Pb(111)
• Interplay Between Yu-Shiba-Rusinov States and Multiple Andreev Reflections
• Investigation of the Yu-Shiba-Rusinov states of a multi-impurity Kondo system

Cited by in corpus (18)

• Diode effect in Josephson junctions with a single magnetic atom
• Pair excitations of a quantum spin on a proximitized superconductor
• Sublattice modulated superconductivity in the Kagome Hubbard model
• Zeeman effects on Yu-Shiba-Rusinov states
• Universal scaling of tunable Yu-Shiba-Rusinov states across the quantum phase transition
• Tracking a Spin-Polarized Superconducting Bound State across a Quantum Phase Transition
• Full Counting Statistics of Yu-Shiba-Rusinov Bound States
• Controlling Majorana hybridization in magnetic chain-superconductor systems
• Microwave Excitation of Atomic Scale Superconducting Bound States
• Andreev spin-noise detector
• Two imaginarity monotones induced by unified $(\alpha ,\beta )$-relative entropy
• Electrically tunable quantum interference of atomic spins on surfaces
• Spin Entanglement -- A Unifying Principle for Superconductors and Molecular Bonding
• Inelastic tunneling through normal and superconducting junctions in the presence of photonic bath within Lindbladian formalism
• Controlling superconducting transistor by coherent light
• Temperature dependent energy gap for Yu-Shiba-Rusinov states at the quantum phase transition
• DC Josephson effect between two Yu-Shiba-Rusinov bound states
• Yu-Shiba-Rusinov States in Ising Superconductors